It is known to treat neurodegenerative diseases, such as Alzheimer's Disease, Parkinson's Disease, Tremor, and Epilepsy, and ischemia of the brain, such as stroke, by electrically stimulating selected portions of the brain. Currently, this is accomplished by first drilling a burr hole through the patient's cranium in order to gain access to the brain tissue. A stimulation lead, and in particular, a lead with multiple electrodes extending along its length, is then introduced through one or more burr holes into contact with the selected brain tissue. In a deep brain stimulation (DBS) procedure, typically used to treat Parkinson's Disease, Tremor, and Epilepsy, the stimulation lead is advanced through a burr hole deep into the brain, e.g., the anterior thalamus, ventrolateral thalamus (Thal), internal segment of globus pallidus (GPi), substantia nigra pars reticulata (SNr), subthalamic nucleus (STN), external segment of globus pallidus (GPe), and neostriatum. In a cortical brain stimulation procedure, typically used to rehabilitate stroke victims, the lead is introduced through two burr holes and placed underneath the dura matter in contact with the cortex of the brain.
Once the lead is properly located in contact with the selected brain tissue, the proximal end of the lead or an extension lead is subcutaneously routed from the burr hole underneath the patient's scalp, down the neck, and into the chest region in electrical connection with an implanted electrical stimulator. The electrical stimulator is programmed either prior to or after the procedure to deliver electrical pulses to the brain tissue via the stimulation lead.
Although the current brain stimulation techniques used to treat neurological disorders have proven to be successful, such techniques are still quite invasive, requiring the cranium to be opened through at least one burr hole. In addition, the need for a burr hole further complicates the procedure—not only requiring the additional step of accessing the patient's cranium while attempting to minimize tissue trauma, but also requiring that the burr hole be capped at the end of the procedure. Also, additional risks are posed by the possibility that the burr hole may become infected and the routing of the stimulation or extension leads through the neck in close proximity to the jugular veins and carotid arteries.
Thus, there remains a need to provide improved methods, apparatus, kits, and systems for therapeutically stimulating tissue.